Some underwater cables are subject to the requirements for disconnectable connections, including electrical connection of a plurality of circuits and tension connection. In the present structure a conical plug surrounds the tension wires and, with increasing tension, slides in a cup to compress the wires. In order to prevent this sliding between the cable and the cup portion of the connector from adversely affecting sealing, a flexible sleeve clamps to both to accomplish a watertight tension termination for the cable. There are a number of applications where an electric cable must be waterproof, must be joinable to similar cables, and must carry tension. One of the applications is in the lowering of equipment into the sea. The equipment being lowered and the weight of the cable cause tension in the cable. When the equipment being lowered requires electric power or has electric signals which should be read, the cable must also include electrical capability isolated from the sea and from other cable components. Manufacturing processes limit the lengths of single cable and practical considerations require that several such cables be connectable and disconnectable so that a cable of the desired length can be assembled. A particularly difficult application of such cables is in the towing of underwater arrays. Exploration and other types of underwater search require the towing of electrically actuated energy and signal source arrays behind moving ships. These arrays must be towed, which causes cable tension, and these cables must be electrically served so as to require a plurality of conductors in the cable. Termination of such cables is difficult to achieve.